RESUMEN
OBJECTIVE: This study was undertaken to evaluate a group B streptococcal protocol in a large community hospital that combined treatment of high-risk patients with rapid screening of low-risk patients. STUDY DESIGN: In a prospective cohort study from 1994 through 1996 laboring patients in a level III community hospital were considered to be at high risk for neonatal group B streptococcal transmission if they were at <37 weeks' gestation, if they had rupture of membranes >12 hours, if they were known carriers of group B streptococci, if they had a temperature > or =100 degrees F, if the gestation was complicated by fetal growth restriction or was a multiple gestation, or if they had a previous neonate infected with group B streptococci. High-risk patients were treated intravenously with antibiotics during labor. Low-risk patients were screened for group B streptococcal antigen by means of a rapid optical immunoassay. Patients with positive screening results were treated. Neonatal morbidity and mortality were evaluated. RESULTS: Two of 9932 infants delivered had group B streptococcal sepsis diagnosed. In the 2 previous years without a protocol 9 cases of neonatal group B streptococcal sepsis had been diagnosed in 8188 deliveries (P =.0287 by Fisher exact test). The 2 cases of group B streptococcal sepsis during the protocol were as follows: 1 infant born to a high-risk mother with delay in treatment and 1 infant born to a low-risk mother with negative results of both culture and rapid screen during labor. During the previous period 7 infected infants had been born to high-risk mothers and 2 had been born to low-risk mothers. The maternal group B streptococcal carriage rate during the study was 18%. Group B streptococcal rapid optical immunoassay sensitivity was 81%. Elapsed time from screening to treatment was < or =2(1/2) hours for 93% of patients. No maternal anaphylaxis, no increase in bacterial neonatal sepsis caused by organisms other than group B streptococci, and no protocol-related group B streptococcal antibiotic resistance were noted. CONCLUSION: Successful implementation and maintenance of a protocol combining treatment of high-risk patients with rapid screening of low-risk patients during labor reduced neonatal group B streptococcal sepsis.
Asunto(s)
Enfermedades del Recién Nacido/prevención & control , Tamizaje Masivo , Complicaciones Infecciosas del Embarazo/diagnóstico , Infecciones Estreptocócicas/diagnóstico , Infecciones Estreptocócicas/prevención & control , Streptococcus agalactiae , Adulto , Portador Sano , Cefazolina/uso terapéutico , Cefalosporinas/uso terapéutico , Estudios de Cohortes , Femenino , Humanos , Recién Nacido , Tamizaje Masivo/efectos adversos , Intercambio Materno-Fetal/efectos de los fármacos , Embarazo , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Estudios Prospectivos , Factores de Riesgo , Infecciones Estreptocócicas/tratamiento farmacológico , Factores de TiempoRESUMEN
The adipocyte hormone, leptin, is secreted in proportion to adipose mass and is implicated in the regulation of energy balance via its central actions on food intake and sympathetic nervous system activity. The placenta was also shown recently to be a possible source of leptin in pregnant women, raising the possibility that the normal relationship between leptin and adiposity may be altered in pre-eclampsia. We therefore sought to assess the extent to which maternal second trimester serum leptin concentrations differed for women who would subsequently develop pre-eclampsia and those who would remain normotensive. This nested case-control study population comprised 38 women with pregnancy-induced hypertension and proteinuria (pre-eclampsia) and 192 normotensive women. Multiple least-squares regression procedures were used to assess the independent relationship between leptin concentrations and risk of pre-eclampsia. Serum leptin concentrations, measured by radioimmunoassay, were highly correlated with maternal pre-pregnancy and second trimester body mass index (r = 0.71 and r = 0.74 respectively; P < 0.001 for both) among normotensive women, and to a lesser extent among women who developed pre-eclampsia (r = 0.29 and r = 0.42; P = 0.09 and 0.02 respectively). Among women with a pre-pregnancy body mass index of < or = 25 kg/m2, pre-eclampsia cases compared with controls had higher mean second trimester leptin concentrations after adjustment for confounding factors. In contrast, pre-eclampsia cases had lower mean leptin concentrations than controls for those women with a pre-pregnancy body mass index above 25 kg/m2. Other factors in addition to the level of adiposity may therefore influence serum leptin concentrations in pre-eclamptic pregnant women. Our results suggest the possibility that leptin, like several other placentally derived substances (e.g. steroid hormones, eicosanoids and cytokines), may be involved in the pathogenesis of pre-eclampsia. Further work is needed to confirm our findings and to assess the metabolic importance and determinants of leptin concentrations in uncomplicated and pre-eclamptic pregnancies.
Asunto(s)
Tejido Adiposo/metabolismo , Preeclampsia/metabolismo , Proteínas/metabolismo , Adolescente , Adulto , Presión Sanguínea/fisiología , Índice de Masa Corporal , Estudios de Casos y Controles , Estudios de Cohortes , Factores de Confusión Epidemiológicos , Femenino , Humanos , Leptina , Obesidad/complicaciones , Preeclampsia/epidemiología , Embarazo , Segundo Trimestre del Embarazo/metabolismo , Factores de Riesgo , Estadística como Asunto , Suecia/epidemiologíaRESUMEN
Preeclampsia is characterized by diffuse vascular endothelial dysfunction. Tumor necrosis factor-alpha (TNF-alpha), which plays a key role in the cytokine network responsible for immunoregulation, is also known to contribute to endothelial dysfunction and other metabolic disturbances noted in preeclampsia. Results from cross-sectional studies and one longitudinal study indicate that TNF-alpha (or its soluble receptor, sTNFp55) is increased in the peripheral circulation and amniotic fluid of women with preeclampsia as compared with normotensive women. Between December 1993 and August 1994, prediagnostic sTNFp55 concentrations (a marker of excessive TNF-alpha release) were measured in 35 women with preeclampsia and 222 normotensive women to determine whether elevations precede the clinical manifestation of the disorder. Logistic regression procedures were used to calculate maximum likelihood estimates of odds ratios and 95% confidence intervals. Mean second trimester (15-22 weeks' gestation) serum sTNFp55 concentrations, measured by enzyme-linked immunosorbent assay, were 14.4% higher in preeclamptic women than in normotensive controls (716.6 pg/ml (standard deviation 193.6) vs. 626.4 pg/ml (standard deviation 158.0); p = 0.003). The relative risk of preeclampsia increased across successively higher quintiles of sTNFp55 (odds ratios were 1.0, 1.3, 2.1, and 3.7, with the lowest quintile used as the referent; p for trend = 0.007). After adjustment for maternal age, adiposity, and parity, the relative risk between extreme quintiles was 3.3 (95% confidence interval 0.8-13.4). These findings indicate that the level of TNF-alpha in maternal circulation is increased prior to the clinical manifestation of the disorder, and they are consistent with the hypothesized role of cytokines in mediating endothelial dysfunction and the pathogenesis of preeclampsia. Further work is needed to identify modifiable risk factors for the excessive synthesis and release of TNF-alpha in pregnancy, and to assess whether lowering of TNF-alpha concentrations in pregnancy alters the incidence and severity of preeclampsia.
Asunto(s)
Antígenos CD/sangre , Preeclampsia/diagnóstico , Receptores del Factor de Necrosis Tumoral/sangre , Adolescente , Adulto , Estudios de Cohortes , Estudios Transversales , Femenino , Humanos , Preeclampsia/sangre , Embarazo , Segundo Trimestre del Embarazo , Receptores Tipo I de Factores de Necrosis Tumoral , Riesgo , Sensibilidad y Especificidad , WashingtónRESUMEN
OBJECTIVE: Trans fatty acids, formed by the partial hydrogenation of vegetable oils, are associated with increases in plasma concentrations of cholesterol, triglyceride, lipoprotein (a), and coronary heart disease risk. Trans fatty acids may also increase platelet aggregation and alter eicosanoid biosynthesis. We studied the relation between maternal dietary intake of trans fatty acids and risk of preeclampsia. METHODS: Maternal intake of elaidic acid, one of the most abundant dietary trans fatty acids and other fatty acids were estimated using gas-liquid chromatography on erythrocytes from 22 women with preeclampsia and 40 normotensive controls. Fatty acids were expressed as the percentage of total fatty acids in erythrocytes. Logistic regression procedures were used to estimate odds ratios and 95% confidence intervals. RESULTS: Mean levels of elaidic acid were 28% higher among preeclamptics (0.43 +/- 0.12) as compared with controls (0.31 +/- 0.12; p < 0.001). After adjusting for confounding factors, women with the highest levels of elaidic acid (median = 0.47) were 7.4 times (odds ratio = 7.4; 95% confidence interval 1.4-39.7) more likely to have had their pregnancy complicated by preeclampsia as compared with those women with the lowest levels (median 0.24). Risk of preeclampsia appeared to increase with increasing levels of elaidic acid (p value for linear trend = 0.05). CONCLUSION: These cross-sectional data suggest that diets high in elaidic acid may be associated with an increased risk of preeclampsia. This hypothesis should be examined in larger longitudinal studies.
Asunto(s)
Eritrocitos/metabolismo , Ácidos Grasos/metabolismo , Ácido Oléico/metabolismo , Preeclampsia/sangre , Estudios Transversales , Femenino , Humanos , Ácido Oléico/administración & dosificación , Ácidos Oléicos , Embarazo , Factores de RiesgoRESUMEN
OBJECTIVE: Elevated maternal serum human chorionic gonadotropin (hCG) is an important marker of Down syndrome. Notably, women with unexplained elevated serum hCG in the second trimester experience a 2- to 5-fold increase risk of preeclampsia. Urinary gonadotropin peptide (UGP), thought to be a metabolite of hCG that is excreted into urine, has recently been shown to be elevated in Down syndrome pregnancies. We sought to examine urinary UGP levels in preeclamptic and normotensive pregnant women. METHODS: We measured UGP levels in urine collected during the third trimester from 18 women with preeclampsia and 20 normotensive controls. UGP levels were determined using enzyme immunoassay and were corrected for dilution using urinary creatinine. Statistical significance testing was done using the Wilcoxon-Mann-Whitney Rank Sum test and Student t test statistics. RESULTS: There was a statistically significant elevation in urinary UGP levels among preeclamptic cases as compared to normotensive control subjects (p = 0.013). Mean urinary UGP levels were 80.7 and 31.3 pmol/mg creatinine for preeclampsia cases and controls, respectively. Elevations in UGP levels among women with preeclampsia as compared with normotensive control subjects persisted after adjustments for possible confounding factors. CONCLUSION: These early findings suggest that elevations in urinary UGP may be a risk marker for preeclampsia. Prospective studies should further clarify the relation between urinary UGP levels and adverse pregnancy outcomes. These results are consistent with results suggesting a role of placental hypoperfusion in the etiology of preeclampsia.
Asunto(s)
Gonadotropina Coriónica Humana de Subunidad beta/orina , Fragmentos de Péptidos/orina , Preeclampsia/orina , Embarazo/orina , Adulto , Estudios de Casos y Controles , Estudios de Cohortes , Femenino , Humanos , Proyectos Piloto , Valores de ReferenciaRESUMEN
Preeclampsia is a systemic disease characterized by diffuse endothelial dysfunction, increased peripheral vascular resistance, coagulation abnormalities, antioxidant deficiency, persistent elevations of maternal leukocyte-derived cytokines, and hyperlipidemia. Fish oil, rich in omega-3 polyunsaturated fatty acids, is known to reduce fasting and postprandial triglycerides and to decrease platelet and leukocyte reactivity; it may also decrease blood pressure. Additionally, omega-3 fatty acids may beneficially influence vessel wall characteristics and blood rheology. In light of the potential beneficial effects of dietary omega-3 fatty acids, we conducted a cross-sectional case-control study to examine the hypothesized exposure-effect relation between maternal dietary intake of marine omega-3 fatty acids and risk of preeclampsia. We measured polyunsaturated fatty acids in erythrocytes obtained from 22 preeclamptic women and 40 normotensive women; we measured polyunsaturated fatty acids as the percentage of total fatty acids from gas chromatography. We employed logistic regression procedures to estimate odds ratios (ORs) and 95% confidence intervals (CIs). After adjusting for confounders, women with the lowest levels of omega-3 fatty acids were 7.6 times more likely to have had their pregnancies complicated by preeclampsia as compared with those women with the highest levels of omega-3 fatty acids (95% CI = 1.4-40.6). A 15% increase in the ratio of omega-3 to omega-6 fatty acids was associated with a 46% reduction in risk of preeclampsia (OR = 0.54; 95% CI = 0.41-0.72). Low erythrocyte levels of omega-3 fatty acids and high levels of some omega-6 fatty acids, particularly arachidonic acid, appear to be associated with an increased risk of preeclampsia.
Asunto(s)
Eritrocitos/metabolismo , Ácidos Grasos Omega-3/administración & dosificación , Preeclampsia/epidemiología , Adulto , Biomarcadores , Estudios de Casos y Controles , Cromatografía de Gases , Estudios Transversales , Ingestión de Energía , Membrana Eritrocítica/química , Ácidos Grasos Omega-3/sangre , Ácidos Grasos Omega-6 , Ácidos Grasos Insaturados/administración & dosificación , Ácidos Grasos Insaturados/sangre , Femenino , Humanos , Preeclampsia/sangre , Embarazo , Análisis de Regresión , Factores de Riesgo , Washingtón/epidemiologíaRESUMEN
The objective of the study was to evaluate the efficacy and safety of preinduction cervical ripening with 0.5 mg of intracervical prostaglandin E2 (PGE2) gel in women with a previous cesarean section. A retrospective cohort study design was used to compare 117 women with one previous cesarean section (VBACS) with 354 nulliparas. Both groups received preinduction cervical ripening treatment with intracervical PGE2 gel. Student's t and chi 2 tests were used to evaluate group differences. Mantel-Haenszel summary risk ratios and 95% confidence intervals were examined in order to assess the relative risk of cesarian section delivery after adjusting for potential confounders. The mean numbers of PGE2 gel applications were 2.4 and 2.5 for VBACS and controls, respectively (p < 0.05). Thirty-nine percent of VBACS entered labor spontaneously as compared with 33% of nulliparas. Mean duration of ruptured membranes (8.2 vs. 12.1 h) and length of labor (20.1 vs. 28.5 h) were reduced among VBACS as compared with controls (p < 0.05). Overall, VBACS had a higher cesarean section rate as compared with controls (49.6 vs. 31.9%; adjusted relative risk = 1.6, 95% confidence interval 1.2-2.1). There were no differences in the occurrence of maternal and fetal morbidity. Overall, the efficacy and safety of 0.5 mg PGE2 gel administered for preinduction cervical ripening in VBACS is comparable to that observed in nulliparas.
Asunto(s)
Cesárea , Dinoprostona , Trabajo de Parto Inducido/métodos , Oxitócicos , Adulto , Cuello del Útero/efectos de los fármacos , Cuello del Útero/fisiología , Estudios de Cohortes , Femenino , Geles , Humanos , Morbilidad , Embarazo , Estudios Retrospectivos , Medición de RiesgoRESUMEN
OBJECTIVE: To determine if pregnant women with normal singletons will continue to have elevated serum human chorionic gonadotropin (hCG), given that they had an elevated serum hCG in the second trimester. METHODS: Nineteen women with second-trimester hCG levels > or = 2.0 multiples of the median, and 20 women with second-trimester hCG levels < 2.0 multiples of the median were the subjects of this investigation. All study participants had serum hCG levels repeated during the third trimester of pregnancy. We used a chi-square test and Student's t test for comparing categorical variables, and the means of continuous variables, respectively. RESULTS: Using the criterion of > or = 2.0 multiples of the median of the comparison group to define hCG elevation, women with elevated second-trimester hCG levels were women with normal second-trimester hCG levels (risk ratio = 3.9; 95% confidence interval 1.6-9.8; p < 0.001). Adjustment for potential confounders did not materially alter the association. CONCLUSION: Women with elevated hCG in the second trimester continued to have elevations in the third trimester. The persistence of elevated hCG levels in pregnancies uncomplicated by fetal anomalies should be evaluated as a clinical marker of adverse pregnancy outcomes.
Asunto(s)
Gonadotropina Coriónica/sangre , Femenino , Humanos , Estudios Longitudinales , Embarazo , Resultado del Embarazo , Segundo Trimestre del Embarazo , Tercer Trimestre del Embarazo , Valores de ReferenciaRESUMEN
OBJECTIVE: To evaluate measurements of maternal serum CA 125 for the diagnosis of abruptio placentae. METHODS: This investigation was conducted at Swedish Medical Center/Seattle from December 1991 through April 1992. During the study period, we identified 21 consecutive patients with a clinical diagnosis of abruptio placentae. In addition, we enrolled two groups of patients whose pregnancies were not complicated by placental abruption (28 preterm controls and 53 term controls). RESULTS: Mean maternal serum levels of CA 125 were significantly higher among women with abruptio placentae (40.6 +/- 29.6 U/mL) than among preterm controls (26.6 +/- 17.2 U/mL) or term controls (22.0 +/- 11.4 U/mL). Using a positive threshold of 35 U/mL, the sensitivity and specificity of maternal serum CA 125 for abruptio placentae were 42.9% (95% confidence interval [CI] 21.7-64.1) and 92.5% (95% CI 85.4-99.6), respectively. CONCLUSIONS: These findings support an earlier report documenting higher mean maternal serum levels of CA 125 among women with pregnancies complicated by abruptio placentae than in control subjects. However, measurement of maternal serum CA 125 does not appear to be a useful marker for the diagnosis of abruptio placentae. At present, clinical diagnosis of abruptio placentae, with the aid of ultrasonography to rule out other causes of late gestational hemorrhage, should be considered the most sensitive and specific method of detecting this pregnancy complication.
Asunto(s)
Desprendimiento Prematuro de la Placenta/diagnóstico , Antígenos de Carbohidratos Asociados a Tumores/sangre , Diagnóstico Prenatal , Desprendimiento Prematuro de la Placenta/sangre , Adulto , Femenino , Humanos , Embarazo , Sensibilidad y EspecificidadRESUMEN
OBJECTIVE: Pregnancy-induced hypertension is believed to be a disorder of the vascular endothelium, possibly focused in the placenta. Markers such as cellular fibronectin appear early in patients in whom pregnancy-induced hypertension develops. We hypothesized that patients with elevated second-trimester levels of human chorionic gonadotropin would have an increased risk for pregnancy-induced hypertension. STUDY DESIGN: We conducted a cohort study, using a database of patients undergoing second-trimester serum screening for Down syndrome and who were delivered at our institution between January 1990 and August 1991. We included all 180 women with human chorionic gonadotropin levels > or = 2.0 multiples of the median. A sequential sample of 369 women with levels < 2.0 multiples of the median served as the referent group. Standard American College of Obstetricians and Gynecologists definitions of pregnancy-induced hypertension and proteinuria were used. RESULTS: Patients with elevated human chorionic gonadotropin levels were at increased risk for pregnancy-induced hypertension (risk ratio 1.7, 95% confidence interval 1.2 to 2.4) and proteinuric pregnancy-induced hypertension (risk ratio 5.1, 95% confidence interval 1.6 to 16.2). Adjusting for potential confounding factors did not alter these associations. CONCLUSIONS: Patients with elevated human chorionic gonadotropin appear to be at higher risk of pregnancy-induced hypertension and proteinuric pregnancy-induced hypertension. Second-trimester human chorionic gonadotropin levels should be further investigated as a potential marker for pregnancy-induced hypertension.
Asunto(s)
Gonadotropina Coriónica/sangre , Hipertensión/epidemiología , Complicaciones Cardiovasculares del Embarazo , Adulto , Biomarcadores , Estudios de Cohortes , Femenino , Humanos , Hipertensión/sangre , Hipertensión/etiología , Oportunidad Relativa , Embarazo , Segundo Trimestre del Embarazo , Estudios ProspectivosRESUMEN
OBJECTIVE: Our purpose was to further evaluate the role of serial amniocentesis in pregnancies complicated by the "stuck twin" syndrome. STUDY DESIGN: A cohort of 37 consecutive cases of stuck twin syndrome was followed up from 1986 through 1992. Evaluations included gestational age at diagnosis and at delivery, mean number of amniocenteses, volume of amniotic fluid withdrawn, placentation, perinatal complications, fetal survival, and neonatal follow-up. RESULTS: Five pregnancies were terminated, five had no intervention, and 27 underwent serial amniocenteses. The mean number of amniocenteses was 3.4 (range 1 to 6), and mean total amniotic fluid volume withdrawn was 5.8 L (range 0.75 to 4.0). In the serial amniocentesis group mean gestational age was 23.1 weeks (range 16 to 30) at diagnosis and 31.5 weeks (range 20 to 38) at delivery. Eighty-two percent had monochorionic placentas, and 36% had marginal or velamentous cord insertions. Infant survival was 39 of 54 (74%) in the serial amniocentesis group compared with four of 10 (40%) in the nonintervention group (relative risk 0.46, 95% confidence interval 0.24 to 0.90). CONCLUSION: Serial amniocentesis was associated with a 54% reduction in fetal and neonatal death in cases of stuck twin syndrome.
Asunto(s)
Amniocentesis , Enfermedades Fetales/terapia , Oligohidramnios/terapia , Polihidramnios/terapia , Embarazo Múltiple , Adolescente , Adulto , Estudios de Cohortes , Femenino , Enfermedades Fetales/mortalidad , Estudios de Seguimiento , Humanos , Recién Nacido , Morbilidad , Oligohidramnios/epidemiología , Oligohidramnios/mortalidad , Polihidramnios/epidemiología , Polihidramnios/mortalidad , Embarazo , Resultado del Embarazo , Resultado del Tratamiento , Gemelos DicigóticosRESUMEN
OBJECTIVE: To determine whether early-gestation vaginal bleeding and elevated maternal serum alpha-fetoprotein (MSAFP) are independent risk factors for adverse infant outcomes. METHODS: We conducted a cohort study of 201 women with an elevated MSAFP (at least 2.0 multiples of the median [MOM]) and a second-trimester ultrasound evaluation at Swedish Hospital Medical Center between January 1989 and March 1991, and 211 women with MSAFP levels below 2.0 MOM who had also undergone ultrasound evaluations during the same period. RESULTS: Stratified analyses demonstrated that early-gestation bleeding and elevated MSAFP were independent risk factors for the delivery of both preterm and low birth weight infants. Compared with women with no history of early-gestation bleeding or elevated MSAFP, women with early-gestation bleeding alone had a relative risk (RR) of preterm delivery of 4.3 (95% confidence interval [CI] 1.5-12.1); non-bleeders with elevated MSAFP had an RR of 4.6 (95% CI 1.9-10.9). A combined history of early-gestation bleeding and elevated MSAFP was associated with an almost sixfold increased risk of preterm delivery (RR 5.8; 95% CI 2.2-15.6). Analyses restricted to women with normal-appearing appearing placentas by second-trimester ultrasound evaluations yielded similar results. CONCLUSIONS: These findings support an earlier report documenting the independence of early-gestation bleeding and elevated MSAFP as predictors of adverse infant outcomes.
Asunto(s)
Retardo del Crecimiento Fetal/epidemiología , Recién Nacido de Bajo Peso , Trabajo de Parto Prematuro/epidemiología , Complicaciones Cardiovasculares del Embarazo/epidemiología , Embarazo/sangre , Hemorragia Uterina , alfa-Fetoproteínas/análisis , Estudios de Cohortes , Femenino , Humanos , Recién Nacido , Complicaciones Cardiovasculares del Embarazo/sangre , Primer Trimestre del Embarazo , Segundo Trimestre del Embarazo , Riesgo , Factores de RiesgoRESUMEN
OBJECTIVE: Unexplained elevations of maternal serum alpha-fetoprotein levels in the second trimester of pregnancy are associated with adverse pregnancy outcomes, including intrauterine growth retardation, preterm delivery, preeclampsia, and abruptio placentae. In addition, elevations of maternal serum alpha-fetoprotein have been associated with placental lesions detected during second-trimester ultrasonographic evaluations. We examined the relationship between adverse pregnancy outcomes and unexplained elevations of maternal serum alpha-fetoprotein and placental abnormalities in the second trimester of pregnancy. STUDY DESIGN: During the period from January 1989 to March 1991 we conducted a cohort study of 201 women with an elevated maternal serum alpha-fetoprotein (> or = 2.0 multiples of the median) and a second-trimester ultrasonographic evaluation at Swedish Hospital Medical Center and 211 women with normal maternal serum alpha-fetoprotein levels who had also undergone ultrasonographic evaluation at the same institution. All women in this investigation had singleton pregnancies without fetal anomalies. RESULTS: Elevated maternal serum alpha-fetoprotein was associated with the following adverse pregnancy outcomes: low birth weight (adjusted risk ratio 3.7), preterm delivery (adjusted risk ratio 3.6), intrauterine growth retardation (adjusted risk ratio 4.0), preeclampsia (adjusted risk ratio 3.8) and abruptio placentae (adjusted risk ratio 4.8). Placental abnormalities detected during second-trimester ultrasonographic evaluations were also associated with adverse pregnancy outcomes: low birth weight (adjusted risk ratio 2.0), preterm delivery (adjusted risk ratio 2.3), intrauterine growth retardation (adjusted risk ratio 1.4), and abruptio placentae (adjusted risk ratio 9.0). A joint positive history of second-trimester elevations of maternal serum alpha-fetoprotein and placental abnormalities was more strongly associated with the following adverse infant outcomes: low birth weight (adjusted risk ratio 6.9), preterm delivery (adjusted risk ratio 5.6), and intrauterine growth retardation (adjusted risk ratio 5.3). CONCLUSIONS: Unexplained elevated levels of maternal serum alpha-fetoprotein and placental abnormalities detected in the second trimester of pregnancy are associated with particularly poor pregnancy outcome. Careful examination for placental abnormalities should be part of the evaluation of elevated maternal serum alpha-fetoprotein.
Asunto(s)
Enfermedades Placentarias/fisiopatología , Resultado del Embarazo , Tercer Trimestre del Embarazo , Embarazo/sangre , alfa-Fetoproteínas/análisis , Peso al Nacer , Femenino , Humanos , Enfermedades Placentarias/diagnóstico por imagen , Ultrasonografía PrenatalRESUMEN
Normal values for Doppler waveform indices of the umbilical artery have been reported for gestational ages of 20 to 40 weeks in small numbers of normal patients. We evaluated 590 patients studies performed at 2-week intervals from 14 to 42 weeks' gestation on patients without medical or pregnancy complications. Readings were obtained during fetal quiet times (no fetal breathing or movements). Values for A (systolic) and B (diastolic) pressures were plotted as Pourcelot (A - B/A) and A/B ratios. Mean, SD, and 95% confidence limits were derived, and the skewness, kurtosis, and regression correlations were calculated. No diastolic flow was found in any pregnancy greater than 15 weeks' gestation (n = 25) or in 50% of the gestations between 15 to 17 weeks (n = 25). When diastolic pressure equals zero, the Pourcelot ratio value equals one and the A/B ratio approaches infinity and loses meaning. Recent work by Thompson et al. suggests that the Pourcelot ratio fits a normal distribution from 20 to 40 weeks' gestation and that the A/B ratio (which does not fit a normal curve) may be transformed to a normal distribution by conversion of the A/B ratio to 1/1 - Pourcelot ratio. Our data supports the normality of both indices from 18 to 42 weeks' gestation, but these assumptions are not applicable as the Pourcelot ratio approaches one or as the A/B ratio approaches infinity. Knowledge of normal umbilical flow ratios at gestational ages from 18 weeks may allow early detection and directed management of high-risk pregnancies.